<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>导航栏下拉菜单</title>
	</head>
	<style>
	ul {
		/*不显示li ul 标志符号*/
	    list-style-type: none;
	    margin: 0;
	    padding: 0;
	    overflow: hidden;
	    background-color: #333;
	}
	
	li {
	    float: left;
	}
	
	li a, .dropbtn {
	    display: inline-block;
	    color: white;
	    text-align: center;
	    padding: 14px 16px;
	    text-decoration: none;
	}
	
	li a:hover, .dropdown:hover, .dropbtn {
	    background-color: #111;
	}
	
	.dropdown {
	    display: inline-block;
	}
	
	.dropdown-content {
	    display: none;
	    position: absolute;
	    background-color: #f9f9f9;
	    min-width: 160px;
	    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
	}
	
	.dropdown-content a {
	    color: black;
	    padding: 12px 16px;
	    text-decoration: none;
	    display: block;
	}
	
	.dropdown-content a:hover {background-color: #f1f1f1}
	
	.dropdown:hover .dropdown-content {
	    display: block;
	}
	</style>
	<body>
		<ul>
		  <li><a class="active" href="#home">主页</a></li>
		  <li><a href="#news">新闻</a></li>
		  <div class="dropdown">
		    <a href="#" class="dropbtn">下拉菜单</a>
		    <div class="dropdown-content">
		      <a href="#">链接 1</a>
		      <a href="#">链接 2</a>
		      <a href="#">链接 3</a>
		    </div>
		  </div>
		</ul>
	</body>
</html>